1. Field of the Invention
The present invention relates to a leadframe used in a semiconductor assembly process, and more particularly to a leadframe manufacturing apparatus using laser beams and a method for manufacturing a leadframe using the same.
2. Description of the Related Art
In general, a leadframe is a core constituent of a packaged semiconductor integrated circuit, providing an electrical connection between the inside and outside of a semiconductor package and also acting as a mechanical support for the semiconductor chip. A leadframe consists of a chip pad for mounting a chip, an inner lead, and an external lead. Generally, there are two ways of manufacturing a leadframe. A stamping method uses a mold to manufacture a leadframe. A sequential transfer-type press machine transfers and presses the material to manufacture the leadframe in a predetermined shape. Even though the stamping method can achieve mass production, it takes 6 to 10 months to prepare a mold and the initial investment for a mold is very expensive. On the other hand, an etching method puts a photoresist layer on a leadframe material, and processes it through photolithography resulting in a leadframe having a predetermined pattern. The etching method is suitable for forming a fine pattern and the development time is short. However, it is difficult and expensive to achieve mass production.
As semiconductor packages require more closely spaced leads, limitations of the above-described two methods have been revealed. The stamping method has mechanical problems due to the weakness of such parts as a punch and die used in a pressing apparatus. The etching method reveals a limitation in achieving a fine pattern.